💎 fix: Gemini Image Gen Tool Vertex AI Auth and File Storage (#11923)

* chore: saveToCloudStorage function and enhance error handling

- Removed unnecessary parameters and streamlined the logic for saving images to cloud storage.
- Introduced buffer handling for base64 image data and improved the integration with file strategy functions.
- Enhanced error handling during local image saving to ensure robustness.
- Updated the createGeminiImageTool function to reflect changes in the saveToCloudStorage implementation.

* refactor: streamline image persistence logic in GeminiImageGen

- Consolidated image saving functionality by renaming and refactoring the saveToCloudStorage function to persistGeneratedImage.
- Improved error handling and logging for image persistence operations.
- Enhanced the replaceUnwantedChars function to better sanitize input strings.
- Updated createGeminiImageTool to reflect changes in image handling and ensure consistent behavior across storage strategies.

* fix: clean up GeminiImageGen by removing unused functions and improving logging

- Removed the getSafeFormat and persistGeneratedImage functions to streamline image handling.
- Updated logging in createGeminiImageTool for clarity and consistency.
- Consolidated imports by eliminating unused dependencies, enhancing code maintainability.

* chore: update environment configuration and manifest for unused GEMINI_VERTEX_ENABLED

- Removed the Vertex AI configuration option from .env.example to simplify setup.
- Updated the manifest.json to reflect the removal of the Vertex AI dependency in the authentication field.
- Cleaned up the createGeminiImageTool function by eliminating unused fields related to Vertex AI, streamlining the code.

* fix: update loadAuthValues call in loadTools function for GeminiImageGen tool

- Modified the loadAuthValues function call to include throwError: false, preventing exceptions on authentication failures.
- Removed the unused processFileURL parameter from the tool context object, streamlining the code.

* refactor: streamline GoogleGenAI initialization in GeminiImageGen

- Removed unused file system access check for Google application credentials, simplifying the environment setup.
- Added googleAuthOptions to the GoogleGenAI instantiation, enhancing the configuration for authentication.

* fix: update Gemini API Key label and description in manifest.json

- Changed the label to indicate that the Gemini API Key is optional.
- Revised the description to clarify usage with Vertex AI and service accounts, enhancing user guidance.

* fix: enhance abort signal handling in createGeminiImageTool

- Introduced derivedSignal to manage abort events during image generation, improving responsiveness to cancellation requests.
- Added an abortHandler to log when image generation is aborted, enhancing debugging capabilities.
- Ensured proper cleanup of event listeners in the finally block to prevent memory leaks.

* fix: update authentication handling for plugins to support optional fields

- Added support for optional authentication fields in the manifest and PluginAuthForm.
- Updated the checkPluginAuth function to correctly validate plugins with optional fields.
- Enhanced tests to cover scenarios with optional authentication fields, ensuring accurate validation logic.

client/src/components/Plugins/Store/PluginAuthForm.tsx

@@ -20,6 +20,7 @@ function PluginAuthForm({ plugin, onSubmit, isEntityTool }: TPluginAuthFormProps
 
   const localize = useLocalize();
   const authConfig = plugin?.authConfig ?? [];
+  const allFieldsOptional = authConfig.length > 0 && authConfig.every((c) => c.optional === true);
 
   return (
     <div className="flex w-full flex-col items-center gap-2">
@@ -38,6 +39,7 @@ function PluginAuthForm({ plugin, onSubmit, isEntityTool }: TPluginAuthFormProps
         >
           {authConfig.map((config: TPluginAuthConfig, i: number) => {
             const authField = config.authField.split('||')[0];
+            const isOptional = config.optional === true;
             return (
               <div key={`${authField}-${i}`} className="flex w-full flex-col gap-1">
                 <label
@@ -55,19 +57,24 @@ function PluginAuthForm({ plugin, onSubmit, isEntityTool }: TPluginAuthFormProps
                       aria-invalid={!!errors[authField]}
                       aria-describedby={`${authField}-error`}
                       aria-label={config.label}
-                      aria-required="true"
+                      aria-required={!isOptional}
                       /* autoFocus is generally disabled due to the fact that it can disorient users,
                        * but in this case, the required field must be navigated to anyways, and the component's functionality
                        * emulates that of a new modal opening, where users would expect focus to be shifted to the new content */
                       // eslint-disable-next-line jsx-a11y/no-autofocus
                       autoFocus={i === 0}
-                      {...register(authField, {
-                        required: `${config.label} is required.`,
-                        minLength: {
-                          value: 1,
-                          message: `${config.label} must be at least 1 character long`,
-                        },
-                      })}
+                      {...register(
+                        authField,
+                        isOptional
+                          ? {}
+                          : {
+                              required: `${config.label} is required.`,
+                              minLength: {
+                                value: 1,
+                                message: `${config.label} must be at least 1 character long`,
+                              },
+                            },
+                      )}
                       className="flex h-10 max-h-10 w-full resize-none rounded-md border border-gray-200 bg-transparent px-3 py-2 text-sm text-gray-700 shadow-[0_0_10px_rgba(0,0,0,0.05)] outline-none placeholder:text-gray-400 focus:border-gray-400 focus:bg-gray-50 focus:outline-none focus:ring-0 focus:ring-gray-400 focus:ring-opacity-0 focus:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50 dark:border-gray-500 dark:bg-gray-700 dark:text-gray-50 dark:shadow-[0_0_15px_rgba(0,0,0,0.10)] dark:focus:border-gray-400 focus:dark:bg-gray-600 dark:focus:outline-none dark:focus:ring-0 dark:focus:ring-gray-400 dark:focus:ring-offset-0"
                     />
                   </HoverCardTrigger>
@@ -82,7 +89,7 @@ function PluginAuthForm({ plugin, onSubmit, isEntityTool }: TPluginAuthFormProps
             );
           })}
           <button
-            disabled={!isDirty || !isValid || isSubmitting}
+            disabled={allFieldsOptional ? isSubmitting : !isDirty || !isValid || isSubmitting}
             type="button"
             className="btn btn-primary relative"
             onClick={() => {